In today’s fledgling economic climate, it’s hard to find any business turning a profit. But don’t count fast-food giant McDonald’s as a company coping with recession. Last month, McDonald’s sales increased 8.2 percent overall, with burgers and fries flying off the frialators in the U.S., Europe and throughout the Asian Pacific, Africa and Middle East.

While I suppose this is good news for the food service sector of the economy, its bad news for the “people” sector.

Everyone knows that fast food is the death nil for physical health, but research from Karolinska Institute in Stockholm, Sweden indicates that it may trigger the downfall of mental decline as well.

In short, double cheese burger fans need to be doubly concerned.

Swedish researcher Susanne Akterin found some troublesome similarities between the chemical makeup in the brains of Alzheimer’s patients and rats fed a diet nutritionally similar to fast food.

There’s no known cure or definitive cause for Alzheimer’s, but every day, more and more puzzle pieces are coming together to help answer this jigsaw puzzle. One of the puzzle pieces Alzheimer’s researchers are focusing on is the protein tau, which appears to build up in excess in Alzheimer’s-afflicted brains.

After feeding rats nine-months worth of a diet high in calories, cholesterol and saturated fat – three hallmarks of the “Super Size Me” diet – Akterin found similarly high amounts of the protein tau in these rats “French fried” brains. In 2002, Northwestern University researchers identified the tau protein as one of the few common threads all brains afflicted with Alzheimer’s have.

The protein anomalies didn’t end there, though. In contrast to the high amounts of tau, Akterin found low amounts of a protein that plays a key role in memory storage, a protein called arc.

The findings were compelling enough for Akterin to say in a statement that a fast-food diet can mess with the brain’s chemical processes so much that it “can be a contributory factor in the development of Alzheimer’s disease.”

As with virtually all studies, more research needs to be done before any advisory information can be relayed to the public about the vast health hazards of fast food.

In the meantime, this is just one more nail in the coffin, more grist for the proverbial mill, more proof in the pudding of fast food’s health hazards. Many people view fast food as an every-once-in-a-while treat. But as rates of obesity and Alzheimer’s continue to rise – not to mention McDonald’s stock price – “every once in a while” may be one too many.